1995 cherokee
4.0 4wd

Ever since I've replaced my flex plate in my jeep it's been running rough. While idling the rpms aren't steady, itll fluctuate between 400-900. Sometimes it'll go all the way down like it's going to die out then shoot up to 900. When I place it in gear she will die out, sometimes immediately. While idling if I give her gas she will pop and backfire through the exhaust. If I press on the gas while in gear (if she stays on long enough) I have minimal power but she does die out fast so I haven't driven it anywhere out of the parking lot of where I live.
I've replaced just about everything I could think of that would cause this issue such as:
Timing chain
Spark plugs & wires
Distributor cap and rotor
All new upgraded fuel injectors
Fuel pressure regulator
Fuel filter
Iacv

Ran tests such as:
Spark test
Compression test
Fuel pressure test

Tested sensors such as:
Crank sensor
Cam sensor
Map sensor
Tps
O2 sensor

I can't seem to figure it out so I towed it to a local shop that's had it for almost 2 weeks now & they can't find the problem also...
So I guess this calls for all JEEP GODS & GURUS!!!
Please help I really miss my jeep

 

Have we unhooked exhaust at manifold to be sure we don't have a clogged cat? Just a thought .

 

Check for the code.
Try to reset the computer(PCM).

 

Whole new exhaust system installed in February...
My 95 is still obd1 (flash code) tried pulling something up multiple times but I'm not getting anything
Also reset the pcm by grounding out the positive and negative terminals to each other

 

If it ran ok with none of the symptoms you describe 'before' the flex plate replace, might want to take that as a clue.

Or did you replace all or any of those parts listed before the flexplate change?